How to spot 12 types of harmful mould in your home

Mould no more!

From an icky annoyance to a silent killer, mould comes in a vast range of varieties and levels of severity, not to mention lots of shapes and colours. With cold and damp weather setting in, we're more likely to keep windows and doors closed and dry our washing indoors, making our homes the perfect breeding grounds for mould. It's not just ugly to look at either, as mould can cause serious health issues, including allergic reactions, respiratory infections, asthma and can even aggravate eczema. Read on to learn more about the most common types and how best to manage them before they can spread.

What is mould?

Mould is a form of fungus that is essentially a collection of spores comprised of fungal secondary metabolites. Although there are hundreds of thousands of species of mould, not all types are dangerous and some are much rarer than others. Mould can form on food, objects, or surfaces and if they are left for too long, the spores reproduce and create mould colonies!

What causes mould?

Mould can be caused by a range of factors, but they pretty much all boil down to moisture – things like condensation, humidity and poor ventilation, all of which create an ideal environment for mould spores to take hold. Prime culprits can be leaking pipes or air conditioners, flooding, a damp basement or porous walls. Let's take a (grim!) look at the most common types found in our homes, according to MyJobQuote.co.uk...

Acremonium

One of the more colourful types of mould, acremonium usually forms in small colonies of pink, orange, grey or white moist patches, which then dry to a powdery consistency. Acremonium is most commonly found around drains, drip pans, humidifiers, HVAC cooling coils and around leaky windows, and can sometimes appear in conjunction with black mould. If this is the case, you’ll need to call in a professional to treat it.

Alternaria

Identifiable by its velvety texture and protruding ‘hairs,’ this dark green or brown mould tends to gravitate towards damp places like bathtubs, shower enclosures and sinks, and is usually an indicator of water damage. Alternaria is quick spreading, but also easy to treat yourself with a good scrub.

Aspergillus

Aspergillus spores are usually grey or green, and most commonly form on wooden surfaces. As these spores can quickly grow into thick layers, aspergillus needs to be handled by a professional if the infestation is significant.

Aureobasidium

While it may start out in shades of pink, brown or black, aureobasidium will shift to a uniform dark brown shade as it matures. Another indicator of water damage, these spores can usually be found under carpets, behind wallpaper or on wooden surfaces. You can treat small aureobasidium infestations yourself with proper protective clothing, gloves and eye protection, but for larger growth, you’ll want to hire a professional.

Chaetomium

Easily identifiable by its musty odour, Chaetomium spores start out white, but darken to grey or brown as they mature. It can usually be found in the same water damage hotspots as aureobasidium, but can frequently be mistaken for black mould, and therefore should be left to professionals.

Cladosporium

This cold-loving spore infestation usually manifests in shades of brown or olive green, with a suede-like texture. Most commonly found on soft furnishings such as curtains, carpets and upholstery (although it may occasionally appear under floorboards as well), cladosporium can be dealt with without professional help if the infestation is small.

Fusarium

While it is most commonly found on food, fusarium can also form on wallpaper, carpets and other water-damaged materials in shades of red, white and pink. This type of spore spreads very quickly, but you can deal with it yourself if you're wearing appropriate clothing and gloves.

Mucor

Usually the result of condensation, this thick grey or white mould can typically be found near leaky windows or doors, or by air conditioners. Mucor is fast-growing and is classed as an allergenic type of mould. Like most infestations, small patches can be dealt with easily, but larger growths require a professional.

Penicillium

Penicillium is typically blue-green in colour and velvety in texture, and is another fast-spreading specimen. These infestations can usually be found in wallpaper, carpets, mattresses and HVAC ducts, and while you can treat smaller infestations yourself, you should call in a professional for larger ones.

Stachybotrys

Dark green or black and slimy in appearance, stachybotrys is more commonly known as black mould, the Darth Vader of spores. Black mould can generally be found in areas that have been exposed to high humidity or water damage for extended periods of time, and usually appears behind walls, on ceilings or on wooden surfaces. You’ll need to bring in a professional to safely dispose of stachybotrys infestations, a process which will need to include the replacement of any infected building materials.

Trichoderma

What’s green, white, and woolly all over? A trichoderma infestation, of course. Typically found on carpets, wallpaper and fabrics, this type of mould is fairly easy to treat yourself with appropriate protective gear. You’ll just want to make sure you deal with the infestation quickly, as it produces an enzyme which attacks textiles, wood and paper, and can even cause damage to building foundations.

Ulocladium

This type of mould usually appears in black clumps in bathrooms, kitchens and basements that have suffered some degree of water damage. When caught early, ulocladium can be dealt with without help. However, if the infestation has been festering for a while, you’ll want to call in a professional.

How to get rid of mould

The first thing to do before treating any kind of mould is to dress appropriately. You don’t want to inhale or come into contact with any of the spores, so make sure to wear goggles, long rubber gloves and a facemask. However, when it comes to most types of household mould removal, all you need is a simple solution of detergent and warm water. Use a sponge or cloth to wipe the mould from your surfaces. Make sure to soak up any excess moisture with the cloth so as to leave the space dry. Open your windows but keep doors closed to prevent spores from spreading to other areas of your home.

Tricky corners

Sometimes mould can form in hard-to-reach corners, particularly in the crevices around showers and sinks, where consistently high levels of moisture create an ideal environment for mould growth. To treat these trouble spots, fill a spray bottle with undiluted white vinegar, thoroughly spray the affected area, and leave it to sit for an hour with the windows open. Then, use a rag and some warm water to wipe off the solution. For stubborn spots, an old toothbrush can help get into tricky corners, but be careful not to release the spores by brushing upwards.

Cleaning mould from hardwood

If mould has formed on your wooden furniture, you can use a solution of dish soap and warm water to wipe down the furnishings. Any lingering stains can be lifted with equal parts white distilled vinegar and water or one part bleach to 10 parts water. However, make sure to spot-test on the underside of the furniture first, as bleach can discolour wood. Leaving to dry in the sun will further help sanitise the surfaces, however, avoid this if using bleach as it can discolour the wood.

Purging soft furnishings

Soft furnishings and carpets can be a bit harder to treat, but it’s equally important to remove mould from them if you start to notice a musty smell. For soft furnishings, you can use a mixture of white vinegar and water, or even shampoo to gently scrub the area. Similarly, you can spray the same solution onto your rug and then cover the area with baking powder. Allow the combo to sit overnight, and then hoover up any residue. However, be careful if you have small children and pets.

How to prevent mould

Fortunately, you can avoid having to resort to any of these measures, as mould is easily preventable with some simple precautionary steps. The best way to prevent mould, of course, is to minimise trapped moisture. When it comes to the bathroom, always make sure the fan is on or the window is open when taking a shower or bath, even in winter! Check that seals around doors, windows and pipes are in good condition to keep your home watertight, especially during cold, damp months.

Reduce moisture

For other spaces, doing things like drying laundry outside (when possible!), using the kitchen fan, keeping lids on saucepans when cooking and regularly opening doors and windows to improve airflow throughout the home can all help keep things fresh. Despite winter approaching and soaring energy bills, try not to let the temperature in your home drop too low, as mould grows more easily in cold spaces. You could also invest in a good dehumidifier.

Keep moisture contained

Of course, in spite of your best efforts to limit damp, some degree of humidity is inevitable as the result of various daily activities. However, this can be minimised by keeping the moisture contained – make sure you close the bathroom door when showering and the kitchen door when cooking, if possible. Regularly wipe down surfaces where you see condensation collecting, like windowsills and cooker hoods, and if you have to dry your clothes indoors, try to keep them contained to one space, ideally behind closed doors.

An indicator of bigger problems?

The short answer is, yes! Mould can be caused by things like leaking pipes, damaged roof tiles, damp basements and porous walls – all problems which will cause plenty of other issues beyond mould growth. Damaged brickwork or leaking pipes within internal walls should be dealt with by a professional and if your property is suffering from rising damp, a builder will need to add a damp-proof course – a barrier which stops water from being absorbed from the ground.

The bottom line

So, what’s the major takeaway? When it comes to mould, it’s always better to be safe than sorry. If you can’t identify a type of mould, are having trouble treating it yourself, or have tried to treat the problem area but the spores keep returning, it’s always a good idea to call in a professional. It’s just not worth the risk to your home and health!

Reference links to original sources may not appear in this version – to view the piece in full, please see www.loveproperty.com.